// Copyright (C) 2014 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.gerrit.server.config;

import com.google.common.collect.ImmutableList;
import com.google.gerrit.extensions.client.SubmitType;
import com.google.gerrit.reviewdb.client.Project;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.jgit.lib.Config;

@Singleton
public class RepositoryConfig {

  static final String SECTION_NAME = "repository";
  static final String OWNER_GROUP_NAME = "ownerGroup";
  static final String DEFAULT_SUBMIT_TYPE_NAME = "defaultSubmitType";
  static final String BASE_PATH_NAME = "basePath";

  private final Config cfg;

  @Inject
  public RepositoryConfig(@GerritServerConfig Config cfg) {
    this.cfg = cfg;
  }

  public SubmitType getDefaultSubmitType(Project.NameKey project) {
    return cfg.getEnum(
        SECTION_NAME,
        findSubSection(project.get()),
        DEFAULT_SUBMIT_TYPE_NAME,
        SubmitType.MERGE_IF_NECESSARY);
  }

  public List<String> getOwnerGroups(Project.NameKey project) {
    return ImmutableList.copyOf(
        cfg.getStringList(SECTION_NAME, findSubSection(project.get()), OWNER_GROUP_NAME));
  }

  public Path getBasePath(Project.NameKey project) {
    String basePath = cfg.getString(SECTION_NAME, findSubSection(project.get()), BASE_PATH_NAME);
    return basePath != null ? Paths.get(basePath) : null;
  }

  public List<Path> getAllBasePaths() {
    List<Path> basePaths = new ArrayList<>();
    for (String subSection : cfg.getSubsections(SECTION_NAME)) {
      String basePath = cfg.getString(SECTION_NAME, subSection, BASE_PATH_NAME);
      if (basePath != null) {
        basePaths.add(Paths.get(basePath));
      }
    }
    return basePaths;
  }

  /**
   * Find the subSection to get repository configuration from.
   *
   * <p>SubSection can use the * pattern so if project name matches more than one section, return
   * the more precise one. E.g if the following subSections are defined:
   *
   * <pre>
   * [repository "somePath/*"]
   *   name = value
   * [repository "somePath/somePath/*"]
   *   name = value
   * </pre>
   *
   * and this method is called with "somePath/somePath/someProject" as project name, it will return
   * the subSection "somePath/somePath/*"
   *
   * @param project Name of the project
   * @return the name of the subSection, null if none is found
   */
  private String findSubSection(String project) {
    String subSectionFound = null;
    for (String subSection : cfg.getSubsections(SECTION_NAME)) {
      if (isMatch(subSection, project)
          && (subSectionFound == null || subSectionFound.length() < subSection.length())) {
        subSectionFound = subSection;
      }
    }
    return subSectionFound;
  }

  private boolean isMatch(String subSection, String project) {
    return project.equals(subSection)
        || (subSection.endsWith("*")
            && project.startsWith(subSection.substring(0, subSection.length() - 1)));
  }
}